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01-6
4WD Automatic Transmission ▶
Torque converter
Oil cooler outletOil cooler return
Inhibiter switch Adapter housing
2) Appearance
Connector plug
Transfer case
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01-73680-01
2WD Automatic Transmission ▶
Torque converter
Oil cooler outletOil cooler return
Inhibiter switch Flange for
propeller shaft
Connector plug
Flange for propeller
shaft
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01-93680-01
3. TIGHTENING TORQUE
Description Size x Numbers Tightening torque
Transfer case housing M12 x 32 54 ~ 68
Etension housing M12 x 32 54 ~ 68
Oil pan M6 x 16 4 ~ 6
Valve body to transmission housing M6 x 26 8 ~ 13
Valve body to transmission housing M6 x 45 8 ~ 13
Center support to transmission housing M10 x 34 20 ~ 27
Output shaft locking nut M24 x 15 100 ~ 110
Pump cover to oil pump M8 x 55 24 ~ 27
Pump cover to transmission housing M8 x 40 24 ~ 34
Pump cover to transmission housing M8 x 58 24 ~ 34
Upper valve body to lower valve body M6 x 30 15 ~ 17
Detent spring M8 x 16 20 ~ 25
Variable bleed solenoid and speed sensor
M4 x 12 2.8 ~ 3.2
Transmission oil level plug 30 ~ 35
Front cooling lines to transmission cooler
25 ~ 35
Rear cooling lines to transmission cooler
25 ~ 35
Drive plate to torque converter
40 ~ 42
Gear select lever to shaft rod
14 ~ 20
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01-16
4. LIMP HOME MODE
In case of transmission malfunction ▶
If a serious fault occurs in the automatic transmission, the TCU enters the limp home mode to
secure safe driving and protect the automatic transmission.
As power is no longer supplied to the solenoid, the current basic function (P, R, N, D) is
maintained and the 4th gear can be maintained only by the operation of the hydraulic system
without electrical operation.
The ECU communicates with other electric modules with CAN. If a serious fault occurs, the
transmission automatically enters the limp home mode for service.
The TCU monitors all factors which can affect to the performance of the transmission and
diagnose the system according to OBD II regulation. 1.
2.
3.
4.
In case of overheated transmission ▶
The TCU enters the limp home mode when the batter voltage drops below 8 V.
If the transmission is overheated, the shift pattern is changed to the hot mode to cool the
transmission more efficiently.
While the transmission is overheated, the selector lever symbol and engine temperature warning
lamp on the instrument cluster blink until the transmission is cooled down to the normal operation
temperature. If the transmission is excessively overheated, the gear cannot be shifted but
remains in the neutral position. 1.
2.
3.
Towing the vehicle with A/T ▶
The best way to transport the vehicle is to load it to a truck and transport it, especially if the vehicle is
4WD.
If towing the vehicle with the propeller shaft connected, the transmission or oil pump of transfer case
may malfunction, resulting in internal damage due to poor lubrication. -
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01-173680-01
5. ELECTRONIC CONTROL SYSTEM
1) Overview
The transmission control unit (TCU) and its input/output networks control the operations of transmission:
Shift timing
Line pressure
Clutch pressure (shift feel)
Torque converter clutch -
-
-
-
In addition, the TCU receives input signals from certain transmission-related sensors and switches. The
TCU also uses these signals when determining transmission operating strategy. Using all of these input
signals, the TCU can determine when the time and conditions are right for a shift, or when to apply or
release the torque converter clutch. It will also determine the pressure needed to optimise shift feel. To
accomplish this, the TCU operates six variable bleed control solenoids and four ON/OFF solenoids to
control the operations of transmission.
2) Transmission Control Unit (TCU)
The transmission control unit (TCU) is mounted under the driver's seat and controls the operation of the
transmission.
TCU processes the analog information from the internal sensors and the digital information through CAN
communication lines. TCU monitors all the input and output signals. If there is any failure, TCU changes
the system to “Limp Home Mode” and alerts to the driver through the warning lamp on the
instrument cluster.
(1) Hard-wired (Analog) Input/Output
Input/Output Data between TGS Lever and TCU ▶
Position and conditions of gear select lever
Driving moded (Winter or Standard) -
-
Position of inhibitor switch - Input/Output Data between Inhibitor and TCU ▶
6 control signals for variable bleed solenoid
4 control signals for ON/OFF solenoid
Transmission input speed
Transmission output speed
Transmission oil temperature
EMM (Embeded Memory Module) -
-
-
-
-
- Input/Output Data between Automatic Transmission and TCU ▶
Input/Output Data between Self Diagnostic Connector and TCU ▶
Various DTC codes and TCU information -
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01-213680-01
Pressure Modulation ▶
To provide a higher level of shift comfort and durability, the hydraulic pressure in the shift related friction
elements of the transmission must be matched accurately to the input torque to transmission. This
hydraulic pressure is composed of a hydraulically pre-set basic pressure and a control pressure which is
set by one of the variable bleed solenoids.
The transmission input torque can be directly calculated from the following operating parameters:
engine torque signals
engine speed or any signal transmitted from ECU through CAN lines
converter slip -
-
-
Separate pressure characteristics for each gear change make it possible to adapt precisely to the
particular shift operation.
5) Shift Mode Selection by TCU
The driver can select Standard (S) or Winter mode (W) with the mode switch. TCU automatically
changes the shift mode according to the transmission oil temperature, uphill or downhill gradient, and
altitude to keep the good driving conditions.
Standard Mode (S) ▶
Uphii and Downhill Mode ▶
Altitude Mode ▶ Standard Mode is selected when setting the mode switch in Standard (S) position with the gear select
<0093008c009d008c0099004700900095004702c8006b02c9004700880095008b0047009b008f008c0047009b009900880095009a00940090009a009a00900096009500470096009000930047009b008c00940097008c00990088009b009c0099008c004700
9000950047009500960099009400880093004700960097008c>rating range. Proper shift timing
provides the optimized fuel economy and good driving conditions.
In this mode, the operating points of torque converter lock-up clutch and the shifting points are adjusted
according to the vehicle weight.
In this mode, the shifting points are automatically adjusted according to the altitude to compensate the
engine torque changes due to barometric pressure and temperature.
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01-22
Winter Mode (W) ▶
Low Range Driving Mode ▶
Warm Up Mode ▶ When the Winter mode is selected, the second gear is engaged to start off the vehicle easily to prevent
wheel spin on slippery surfaces and WINTER mode indicator comes ON. The first gear is not available
in this mode.
When the vehicle is in 4L driving mode, the transmission uses a different shift mode to optimize the low
range driving. Similar to Winter mode, the first gear is not available.
This mode is normally used when the transmission oil temperature is below 20°C.
<007b008f008c0047009b009600990098009c008c0047008a00960095009d008c0099009b008c00990047008a0088009500950096009b00470089008c004700930096008a0092008c008b0054009c009700470089008c00930096009e00470059005700b600
6a0047009b00960047009700990096009d0090008b008c0047>the warming up process of
transmission.
Hot Mode ▶
<0070008d0047009b008f008c0047009b009900880095009a00940090009a009a00900096009500470096009000930047009b008c00940097008c00990088009b009c0099008c00470090009a00470089008c009b009e008c008c0095004700580058005700
b6006a004700880095008b00470058005b005c00b6006a0053> the system provides the cooling
and reduces the load to the transmission. This is called Hot Mode.
Above 110°C:
Above 130°C:
Above 145°C: -
-
-
In Hot Mode, any of shift mode is not available.
Cruise Control ▶
When the cruise control is activated, the engine ECU requests the downshift to increase the engine
brake effect.PWM fan ON
the engine torque is reduced and WINTER indicator is blinking
the transmission is held in Neutral (N) gear until the oil temperature falls below
120°C (Final protection)
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01-253680-01
1) Power Flow - Manual (M Position)
Functioning elements ▶
Control ▶C2 applied, FSG (Forward Sun Gear)
driven
B2 applied to hold Rear Planet Carrier
stationary
Provides engine breake effect -
-
-
S1 ON, C1 shift valve moved to the left end, C1 clutch not engaged
S1 ON, B2 shift valve moved to the left end, B2 band operated (S7 should be ON)
C2 shift valve open (S2 OFF), C2 clutch engaged by drive oil
Drive oil (for C2 clutch engagement) is regulated by VBS S6 -
-
-
-
Connecting Components ▶
Gear
ratioON / OFF solenoids Variable pressure sol. valve-VBS
S1 S2 S3 S4 S5(A) S6(A) S7(A) S8(A) S9(A) S10(A)
3.53 ON 1 0 1 0-1
Gear
ratioEngaged element
C1 C2 C3 B1 B2 OWC Lock-up
clutch
AO AI R AO AI
3.53 ON ON ON
Power Flow Diagram ▶
Manual 1st gear is not engaged even when
moving the manual valve to a certain position.
This gear state is obtained electronically by
solenoids S1 and S7.